So he has always been on his toes, expecting assassination. There for all attempts by time travelers have failed. This has caused his time line to become locked as any more attempts could cause a complete breakdown of time itself.
His unique stance is actually the optimal position to be in to defend against a sudden future martial arts attacks. He had to instantly teach it to himself during the first attempt, since no one has even seen these types of attacks yet, but he did it, and survived. They say no one else could have done it but him.
So he has always been on his toes, expecting assassination. There for all attempts by time travelers have failed. This has caused his time line to become locked as any more attempts could cause a complete breakdown of time itself.
His unique stance is actually the optimal position to be in to defend against a sudden future martial arts attacks. He had to instantly teach it to himself during the first attempt, since no one has even seen these types of attacks yet, but he did it, and survived. They say no one else could have done it but him.